JPH06316895A - Method for dyeing paper with disazo dye - Google Patents

Abstract

PURPOSE: To dye paper with superior blue color and high light-fastness by using a specified disazo dye. CONSTITUTION: A dye expressed by formula I A is formula II or formula III [X1 and Y are each H, an alkyl, an alkoxy, NHCO-Z (Z is H, an alkyl, an aryl, an alkoxy, amino, a mono- or di-alkylaminoarylamino; (m) is 0 or 1)]; R1 is H, an alkyl, an alkoxy, a halogen, SO3 M, carboxyl (M is H or a monovalent colorless cation; (n) is 1 or 2}, particularly a dye in which X and Y are each H, methyl or methoxy, R1 is H or SO3 M, is used to dye paper with wet, superior blue color and high light-fastness. The dye has high solubility. It is superior in storage stability even at a low temp. of 0-5 deg.C as a concentrated aq. soln. (particularly at pH 12) and it exhibits a high absorption rate. As the dye, the dye obtained by diazotizing an amino compd. of formula IV and coupling the diazotized product with a compd. of formula V. is particularly preferable.

Description

Detailed Description of the Invention

Disazo dyes are often used to dye paper in blue shades. In the case where high light fastness properties of the dyeings are desired, the copper complex salts of the dyes are practically almost exclusively used. Recently, lightfast blue dyes for paper which are not copper complex salts have been sought for economic and ecological reasons. The required dye must further satisfy the following conditions. That is, it exhibits a high exhaustion rate under a specific dyeing condition, gives a dyeing product having good wet fastness, and manufactures a product in a liquid form which easily dissolves, that is, a concentrated solution of the dye. Is possible. All of these conditions are not yet satisfied by the blue dyes for paper currently available.

The object of the present invention is therefore to provide a process for dyeing paper in blue which satisfies the above conditions to the maximum possible extent. This object is achieved by the method of the invention described below. That is, the present invention relates to a method for dyeing paper, and the method of the present invention is characterized by using a dye of the following formula.

[Chemical 7] In the formula, A is a group of any of the following formulas:

[Chemical 8] (The symbols in the formula have the meanings given below), X and Y are independently of each other hydrogen, alkyl, alkoxy, or -NH.
-CO-Z (wherein, Z is hydrogen, alkyl, aryl, alkoxy, amino, mono - or di - alkylamino or arylamino,) a, R ₁ is hydrogen, alkyl, alkoxy, halogen, SO ₃ M or carboxyl, M is hydrogen, or a monovalent colorless cation, n is 1 or 2, and m is 0 or 1.

In the present invention, alkyl groups are generally straight chain.
It is understood that it means a chain, branched or cyclic alkyl group.
I want you to understand. Cyclic alkyl is preferably 5 to 8 carbons
Containing an elementary atom, and the open chain alkyl is preferably 1
It contains up to 8 carbon atoms. Linear or branched open chain
Alkyl is, for example, methyl, ethyl, n-propyl,
Isopropyl, n-butyl, sec-butyl, tert
-Butyl, n-pentyl, isopentyl, n-hexyl
Or isohexyl or 2-ethylhexyl. This
These alkyl groups should be mono- or poly-substituted.
You can Substituents are, for example, hydroxyl, sulfo,
Carboxyl, C₁ -C_Four-Alkoxy, hydroxyl
Conversion C₁ -C_Four-Alkoxy, phenyl, phenoxy, also
Is phenylaminocarbonyl. Of the last three groups
Phenyl in is, for example, sulfo, C ₁ -C_Four-Archi
Le, C₁ -C_Four-By alkoxy or phenoxy
Can be replaced. Such substituted alkhi
Group is, for example, hydroxyethyl, 1-hydroxy-
Isopropyl, ethoxy-methyl, 2-hydroxyeth
Xy-phenyl, benzyl, 1-phenylethyl, 2-
Phenylethyl, 1-methyl-2-phenylethyl, 1
-Isobutyl-3-phenylpropyl, 1,5-diphe
Nyl-3-pentyl, 1-methyl-2-phenoxyethyl
1-methyl-2-phenylaminocarbonyl-ethyl
Such as Le. Cycloalkyl is especially cyclopentyl
And cyclohexyl. C as a substituent₁ -C_Four-A
Rukiru, special CH₃ Can be given.

Suitable alkoxy groups preferably have 1 to 4 carbon atoms and are, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy.
These alkoxy groups can also be substituted, for example, by the substituents mentioned above for the alkyl groups, especially hydroxyl or C ₁ -C ₄ -alkoxy. Substituted alkoxy groups are, for example, hydroxyethoxy, methoxyethoxy, 2-hydroxypropoxy, 1,2-dihydroxy-3-propoxy, or 1,2-dimethoxy-3-.
It is propoxy.

Halogen is to be understood as meaning fluorine, bromine, iodine, or especially chlorine. An aryl group is to be understood here to mean in general an aromatic or aromatic heterocyclic group, in particular a naphthyl group, or more preferably a phenyl group. These groups are
All may or may not be replaced. Examples of substituents are C ₁ -C ₄ -alkyl, C ₁ -C ₄ -alkoxy, bromine, chlorine, nitro, cyano, sulfo, carboxyl or C ₁ -C ₄ -alkylcarbonylamino. However, a particularly preferred aryl is phenyl.

M is hydrogen, or a monovalent colorless cation such as lithium, sodium, potassium, ammonium, or a protonated form of C ₄ -C ₁₂ trialkylamine, C ₄ -C ₁₂ diamine, or C _2. -C is ₁₅ alkanolamine. Protonated C ₄ -C ₁₂ trialkylamine for M is, for example, protonated N-ethyldimethylamine, N, N-diethylmethylamine, tri-n-propylamine, tri-n-butylamine, Tri-isobutylamine, and especially triethylamine or triisopropylamine. Mixtures of different protonated amines are also suitable.

Protonated C ₄ -C ₁₂ which means M
Diamines have, for example, one or both of their N atoms being 1
Ethylenediamine or 1,3-diaminopropane substituted by one or two C ₁ -C ₄ -alkyl groups, preferably methyl or ethyl groups. in this case,
Preferably M is N, N-dialkylethylenediamine or N, N-dialkyl-1,3-diaminopropane. For example: N-ethylethylenediamine, N,
N-dimethylethylenediamine, N, N'-dimethylethylenediamine, N, N-diethylethylenediamine,
3-dimethylamino-1-propylamine and 3-diethylamino-1-propylamine. Protonated C ₂ -C ₁₅ alkanolamines as M are, for example, the protonated forms of monoalkanolamines, dialkanolamines, monoalkanolmonoalkylamines, monoalkanoldialkylamines, dialkanolalkylamines or trialkanols. It is an amine or a mixture of different protonated alkanolamines. Examples are the protonated amines: 2-aminoethanol, di (2-hydroxyethyl) amine, N- (2-hydroxyethyl) dimethylamine, N- (2-hydroxyethyl) diethylamine, N, N-di (2-hydroxyethyl) methylamine, N, N-di (2-hydroxyethyl) ethylamine, tri (2-hydroxyethyl) amine, 2-aminoethoxyethanol, diethylaminopropylamine.
Protonated polyglycol amines are also suitable.
For example, diethanolamine tris-glycol ether can be used.

M is preferably Na ⁺ , Li ⁺ or a protonated C ₄ -C ₆ -alkanolamine.
A preferred C ₄ -C ₆ -alkanolamine is tri (2-
Hydroxyethyl) amine, di (2-hydroxyethyl) amine, or a mixture of the two amines.

Z is preferably C ₁ -C ₄ -alkyl, substituted or unsubstituted phenyl, amino, or substituted or unsubstituted phenylamino, particularly preferably methyl, phenyl, Amino or phenylamino.

X and Y are preferably hydrogen, methyl,
Methoxy, acetylamino, benzoylamino, ureido or phenylureido, particularly preferably hydrogen, methyl or methoxy. R ₁ is preferably hydrogen, methyl, methoxy, chlorine, SO ₃ M or carboxyl,
Particularly preferred is hydrogen or SO ₃ M.

A particularly preferred embodiment of the method of the invention is
A dye of the formula below is used.

[Chemical 9] In the formula, X and Y are independently of each other hydrogen, methyl, methoxy, or -NH-CO-Z (wherein Z is methyl, phenyl, amino, or phenylamino).
And R ₁ is hydrogen, methyl, methoxy, chlorine, or S
O ₃ M, M is hydrogen or a monovalent colorless cation, and n is 1 or 2.

Among them, particularly preferable dyes are dyes of the following formula.

[Chemical 10] In the formula, X and Y are each independently hydrogen, methyl or methoxy, R ₁ is hydrogen or SO ₃ M, and M is hydrogen or a monovalent colorless cation.

The dyes of the formula (1) used in the process according to the invention for dyeing paper are known or can be prepared by processes known per se. However, these dyes have hitherto been used only for dyeing cotton. Surprisingly, it has now been found according to the invention that these dyes are very suitable for dyeing paper and that the resulting dyeings have excellent lightfastness.

In recent years, the use of concentrated aqueous dye solutions has been emphasized. This is because the solution form has several advantages over the dye in powder form. That is, the use of a solution avoids the difficult problems associated with dust generation and frees the user from the time consuming and often difficult solubilizing work of dissolving dye powders in water. The development of continuous dyeing methods for paper has further promoted the use of concentrates. This is because these continuous processes have the advantage that the concentrated liquid can be added directly to a pulp beater (hollander) or any other suitable place in the papermaking process.

However, when using concentrated aqueous solutions of anionic dyes, such solutions do not have sufficient storage stability, and precipitation occurs within a storage period of several months, especially at about 0 to 5 ° C. So often difficult problems arise. Thus, this time, a concentrated aqueous solution of the dye according to the invention is such that it is at least 0.1 per mole of dye of formula (1).
Containing a molar Li ⁺ , preferably a pH of at least 11
It has been found to have very good storage stability if it has a value.

The invention therefore also relates to an aqueous solution of a dye, which aqueous solution comprises from 2 to 20% by weight of the dye of the formula

[Chemical 11] Where A, M, R ₁ and n are as defined above for formula (1) and at least 0.1 mole of Li ⁺ per mole of dye of formula (1). It is characterized by Among these, a dye aqueous solution having a pH of at least 11, preferably 11 to 13, is preferable. A preferred aqueous dye solution comprises 6 to 15% by weight of the dye of formula (1) and 0.1 to 3 mol of Li ⁺ per mol of dye of formula (1) and has a pH of at least 11. There is.

Even more preferred are aqueous dye solutions containing not more than 2% by weight of inorganic salts, based on the weight of the dye solution. If the salt concentration of the dye solution obtained during the synthesis is higher, this solution can be desalted by conventional methods, for example by a membrane separation method. A pH value of at least 11 of the dye solution according to the invention is a strong base such as NaOH, KOH, ammonia,
It can be adjusted by addition of diethanolamine or triethanolamine, but preferably by addition of Li OH.

The dye solution according to the present invention may further contain the following components. Water-soluble organic solubilizers such as urea, ε-caprolactam, dimethylsulfoxide, N-methylpyrrolidone, water-miscible polyhydric alcohols such as ethylene glycol, propylene glycol or glycerol, alkanolamines such as ethanolamine or triethanolamine, or also poly. Reaction products of glycolamines such as ammonia or alkylamines or hydroxylamines with alkylene oxides such as ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide or 2,3-butylene oxide in suitable quantitative ratios. Such polyglycolamines are known, for example, from German Patent No. A-2061760.

The concentrated aqueous solution of the dye of the formula (1) according to the present invention can be produced, for example, by the following method.
That is, the dye suspension obtained in the dye making process is filtered and, if appropriate, desalted, for example by means of a membrane separation method, followed by a lithium salt and / or lithium hydroxide and, if appropriate, Further, a solubilizing agent is added to stabilize. However, it is also possible to suspend the isolated dye in hydrochloric acid, filter again and mix the filter cake with lithium hydroxide and / or the appropriate lithium salt and the required amount of water. Furthermore, the coupling can also be carried out in the presence of LiOH or alkanolamine and then the synthesis solution can be desalted.

The aqueous dye solution according to the invention is stable on storage at low temperatures up to -5 ° C. and is suitable for dyeing paper.
The paper is dyed a nice blue color and exhibits high lightfastness with and without sizing. The dye solutions can be used by all dyeing methods known in the paper industry for direct dyes. Particularly used for pulp dyeing starting from bleached or unbleached cellulose of various origins such as softwood or hardwood sulfite cellulose and / or sulfate cellulose, and for surface dyeing of size-grade or non-size-grade paper can do.

The present invention further relates to dyes of the formula

[Chemical 12] In the formula, X is hydrogen, alkyl, alkoxy or -NH-
CO-Z (where Z has the meaning given below),
Y ′ is C ₁ -C ₄ -alkoxy, which is substituted by hydroxyl, C ₁ -C ₄ -alkoxy, sulfo, carboxyl, phenyl, phenoxy or phenylaminocarbonyl, Z is hydrogen, alkyl, aryl, Alkoxy, amino, mono- or di-alkylamino, or arylamino, R ₁ is hydrogen, alkyl, alkoxy, halogen, SO ₃ M or carboxyl, M is hydrogen or a monovalent colorless cation,
n is 1 or 2, and m is 0 or 1. X,
Z, R _1, M, n and m are preferably are as defined as preferred with respect to the dye of formula (1), and Y 'is preferably C ₁ -C ₄ substituted by hydroxyl or methoxy - It is an alkoxy.

The new dyestuff of the formula (6) can be produced by a method known per se. Expression

[Chemical 13] Diazotization of the aminoazo compound of

[Chemical 14] It can be produced by coupling with a compound of In the above formulas (7) and (8), X,
Y ′, M, n and R ₁ are as defined in formula (6). Hereinafter, the present invention will be further described with reference to examples. The parts in the examples are parts by weight and the temperature is in degrees Celsius.

Example 1 Formula

[Chemical 15] 60.8 g of the above compound are dissolved in 350 ml of water under neutral conditions with sodium hydroxide solution, together with 6.9 g of sodium nitrite, and 19.2 g of 32% hydrochloric acid are added at 20-25 ° C. Diazotize. The suspension of the obtained diazotized product was added to a solution of 34.5 g of 6-anilino-1-hydroxynaphthalene-3-sulfonic acid and 22 g of diethanolamine in 250 ml of water.
Add dropwise at 5-30 ° C over 45 minutes. During this operation, the pH is kept at 8.5 to 9.0 by adding 18.0 g of diethanolamine. Once the coupling is complete, add 50% sodium hydroxide to the synthetic solution.
40 g of solution are added and the hydrolysis is carried out at 75 ° C. for 1 hour. After cooling to room temperature, the pH is adjusted to 6.5 to 7 with 32% hydrochloric acid. A suspension is obtained which contains a dye of the formula

[Chemical 16] The dye suspension is desalted by reverse osmosis at 50 ° C. using a chemically modified polyacrylonitrile membrane and concentrated to a final weight of 750 g. Then 2 to 5 ° C
A liquid dye formulation was obtained which was stable for several months at.

Example 2 By the method described in Example 1, but this time 40 g of diethanolamine instead of 3 g of sodium hydroxide.
29 g of a 0% solution were used to prepare a dye suspension containing 85.9 g of the trisodium salt of the dye described in Example 1. The resulting suspension was then desalted by reverse osmosis at 50 ° C. using a chemically modified polyacrylonitrile membrane and concentrated to a final weight of 750 g. LiOH ・ 1H ₂ O
3.9 g and anhydrous Li ₂ SO ₄ 3.9 g were added and the solution was stirred at 50 ° C. for 1 hour. After this time, it was cooled to 25 ° C., adjusted to 780 g with deionized water and filtered. The dye solution obtained is stable for several months at a storage temperature of 2 to 5 ° C. and dyes papers with excellent lightfastness.

Example 3 The procedure described in Example 2 was repeated. However, this time Li
Instead of 3.9 g of OH ・ 1H ₂ O and 3.9 g of anhydrous Li ₂ SO ₄
11.7 g of Li ₂ SO ₄ was used. A storage-stable liquid dye formulation was likewise obtained.

Example 4 The procedure described in Example 1 was repeated. However, this time, instead of diethanolamine, a total of 9.9 g of LiOH.1H ₂
O was used for coupling. A storage-stable liquid dye formulation was likewise obtained.

Example 5 70 parts of chemically bleached sulphite pulp (manufactured from softwood) and 30 parts of chemically bleached sulphite pulp (manufactured from birch) were beaten in 2000 parts of water in a beating machine (Hollander).
To this pulp was added 2.5 parts of the dye solution described in Example 1. After mixing for 20 minutes, paper was made from this pulp. The absorbent paper thus obtained was dyed blue. The dyed product had high light fastness. The wastewater was virtually colorless.

Example 6 3.0 parts of the dye solution described in Example 1 are dissolved in 100 parts of water and this solution is added to 100 parts of chemically bleached sulfite pulp beaten in 2000 parts of water in a beater. did. After mixing well for 15 minutes, the resin size and aluminum sulfate were used and sized by a conventional method. The paper produced from this pulp is dyed blue and has excellent wet and light fastnesses.

Examples 7-13 The following dyes were prepared by a method similar to that described in Example 1. These dyes dyed paper in a blue color with excellent fastness.

[Chemical 17]

[Chemical 18]

Examples 14-16 The following dyes were prepared by a method similar to that described in Example 1. These dyes dyed paper in a blue color with excellent fastness.

[Chemical 19]

Examples 17-22 The following dyes were prepared by a method similar to that described in Example 1. These dyes dyed paper in a blue color with excellent fastness.

[Chemical 20]

[Chemical 21]

Examples 23-25 The following dyes were prepared by a method similar to that described in Example 1. These dyes dyed paper in a blue color with excellent fastness.

[Chemical formula 22]

Claims (12)

[Claims] 1. A method for dyeing paper, which comprises using a dye of the following formula: [Wherein A is a group of any of the following formulas: (The symbols in the formulas have the meanings given below) X and Y are independently of each other hydrogen, alkyl, alkoxy, or -NH-.
CO-Z, where Z is hydrogen, alkyl, aryl, alkoxy, amino, mono- or di-alkylamino, or arylamino, R ₁ is hydrogen, alkyl, alkoxy, halogen, SO ₃ M Or carboxyl, M is hydrogen or a monovalent colorless cation, n is 1 or 2, and m is 0 or 1.]. 2. X and Y independently of one another are hydrogen, methyl, methoxy, acetylamino, benzoylamino, ureido or phenylureido, in particular hydrogen, methyl,
The process according to claim 1, wherein a dye of formula (1) which is or is methoxy. 3. R ₁ is hydrogen, methyl, methoxy, chlorine, S
O ₃ M, or carboxyl, especially hydrogen or SO ₃ M
3. A process according to claim 1 or 2, wherein the dye of formula (1) is 4. A process according to claim 1, wherein a dye of the formula: is used. [Wherein, X and Y are independently of each other hydrogen, methyl, methoxy, or -NH-CO-Z (wherein Z is methyl, phenyl, amino or phenylamino).
And R ₁ is hydrogen, methyl, methoxy, chlorine, or S
O ₃ M, M is hydrogen or a monovalent colorless cation, and n is 1 or 2.]. 5. A process according to claim 1, wherein a dye of the formula: is used. Where X and Y are independently of each other hydrogen, methyl or methoxy, R ₁ is hydrogen or SO ₃ M, and M is hydrogen or a monovalent colorless cation. 6. A process according to claim 1, wherein a dye of the formula (1) is used in which M is lithium. 7. A dye of the following formula: 2 to 20% by weight Where A, M, R ₁ and n are as defined for formula (1) of claim ₁ and at least 0.1 mole of Li ⁺ per mole of dye of formula (1). Dye aqueous solution. 8. At least 11, preferably 11 to 1
The aqueous dye solution according to claim 7, which has a pH value of 3. 9. A dyestuff of formula (1) containing 6 to 15% by weight and 0.1 to 3 moles of Li ⁺ per mole of dyestuff of formula (1) and having a pH value of at least 11. Item 7
Or an aqueous solution of the dye according to item 8. 10. 2% by weight, based on the weight of the dye solution
The dye aqueous solution according to any one of claims 6 to 9, which contains less inorganic salts. 11. A dye of the formula: [In the Formula, X is hydrogen, alkyl, alkoxy, or -NH.
A -CO-Z (Z have the below meanings), Y 'is C ₁ -C ₄ - alkoxy, which is hydroxyl, C
₁ -C ₄ - alkoxy, sulfo, carboxyl, phenyl, which is substituted by phenoxy or phenylaminocarbonyl, Z is hydrogen, alkyl, aryl, alkoxy, amino, mono - or di - alkylamino or arylamino, R ₁ is hydrogen, alkyl, alkoxy, halogen, SO ₃ M or carboxyl, M is hydrogen or a monovalent colorless cation, and n is 1
Or 2 and m is 0 or 1.]. 12. In the formula, X is hydrogen, methyl, methoxy or —NH—CO—Z, Z is methyl, phenyl,
Amino or phenylamino, Y ′ is C ₁ -C ₄ -alkoxy substituted by hydroxyl or methoxy, R ₁ is hydrogen, methyl, methoxy, chlorine or SO ₃ M and M is hydrogen or mono. The dye according to claim 11, wherein the dye is a valent colorless cation and n is 1 or 2.